Excavating bucket



1938. J. M. ROBERTS EXCAVATING BUCKET Filed Dec. 13, 1957 2 Sheets-Sheet l INVENTOR. .Jn I ["LRub rts A TTORN E YS.

Nov. 15, 1938. J. M. ROBERTS EXCAVATING BUCKET Filed Dec. 15, 1957 2 Sheets-Sheet 2 INVENTOR. JD 21 M Roberts 5, 'fi; TORN S Patented Nov. 15, 1938 PATENT OFFICE 4 Claims.

T is invention appertains. to excavating dev c s. andmnre pa ticularly to rab. or clam shell buckets;

.One of the nrimaryqbjects, of my nvention is t provide nov means. for const uctin nd D.- l ng a. grab bucket, whereby the. usual omplicat d arran m nt. of heav Operatin ab es and sheaves and awkward bucket head is elimated.

Another salient object of my invention is to provide a grab bucket having a novel arrangement of hydraulic operating means for opening and closing the jaws of the bucket, whereby a compact and durable structure will be had, which will be simple and easy to operate.

A further object of my invention is to provide a grab bucket embodying a supporting frame or platform on which is rockably mounted the bucket jaws, the platform also supporting the pump, operating motor, the hydraulic rams, the

rams being operatively connected to the jaws and platform.

A still further object of my invention is to provide novel means for operating the bucket jaws, which consists in a reversible electric motor for operating a rotary pump in either direction, whereby upon reversing of the motor, the fluid under pressure can be forced to either end of the ram cylinders for operating the ram pistons in the desired direction for opening or closing the Jaws.

With these and other objects in view, the invention consists in the novel construction, arrangement, and formation of parts, as will be hereinafter more specifically described, claimed, and illustrated in the accompanying drawings, in which drawings:

Figure l is an end elevation of my improved grab bucket, showing the same in its closed position.

Figure 2 is a perspective view of the improved grab bucket, showing the same in its open position.

Figure 3 is a top plan view of the bucket, showing the same in its closed position.

Figure 4 is a detail sectional view taken substantially on the line 4-4 of Figure 2, looking in the direction of the arrows.

Referring to the drawings in detail, wherein similar reference characters designate corresponding parts throughout the several views, the letter B generally indicates my improved grab bucket, which includes a supporting frame 5. This frame 5 is in the nature of a platform, and thus the same embodies a bottom wall 6, having side andend. flanges I and 8. flanges support the spaced parallel shafts 9 .and ID on which are mounted, for swinging movement, the bucket jaws II and I2. These jaws II and I2 can be constructed in any preferred manner and of any size tov suit the character of the work being done.

Theupper edges of the jaws H and I2 have secured thereto lift cables I3, and thesecables are employed for the sole purpose of raising and lowering the bucket and do not constitute the operatingmeans for the jaws at all. The bucket also has formed or secured to the upper edges of the jaws, upstanding pairs of arms I4, the purpose of which will be hereinafter more fully set forth.

The bottom wall 6 of the frame 5 has rigidly secured to its central portion a bearing bracket I5, and this bearing bracket has rockably secured to its opposite ends, as at I6, the cylinders I! for the hydraulic rams I8. These cylinders for the rams have reciprocally mounted therein the usual ram pistons, and the piston rods I9 thereof extend exteriorly of the cylinders and are pivotally connected to the arms I4, as at 20.

A rotary or like pump 2| is secured to the platform or frame 5 adjacent the cylnders, and the inner ends of the cylinders are connected by means of conduits 22 with one port of the pump, and the outer ends of the cylinders are connected by conduits 23 with the other port of the pump. The pump is operated by a reversible electric motor 24, and the cable for the motor extends to the control cab of the excavating machine, and a switch is provided for reversing the motor, when necessary.

By reversing the electric motor, the pump 2| can be driven in opposite directions, and, hence, in one instance the pump will intake fluid from the outer ends of the cylinders and force the fluid under pressure to the inner ends of the cylinders. When the pump is rotating in the opposite direction, fluid is drawn from the inner ends of the cylinders and is forced under pressure into the outer ends of the cylinders.

In operation of my improved grab bucket, the same is lowered by the cables I3, and the motor is operated for taking fluid from the inner ends of the cylinders and forcing fluid under pressure intothe outer ends of the cylinders. Thus, the pistons of the hydraulic rams will be moved inwardly, which will swing the jaws on their pivot shafts III, and consequently the jaws will be opened. After the jaws engage the material to be lifted, the electric motor is reversed, so as to The side drive the pump in the opposite direction, and fluid under pressure will be pumped into the inner ends of the cylinders and will be drawn from the outer ends of the cylinders. This will move the pistons outwardly and forcibly swing the jaws H and [2 on their pivots to a closed position.

From the foregoing description, it can be seen that I have provided an exceptionally simple and durable form of grab bucket, in which the jaws can be expeditiously opened and closed by hydraulic rams. v

While I have shown, described, and claimed the pistons connected with the jaws, and the cylinders connected with the frame, it is tobe understood that this construction can be reversed, and, in some instances, I contemplate connecting the cylinders with the jaws, and the pistons with the franie.

Other changes-in details may be made without departing from the spirit or the scope'of my invention, but what I claim as new is:

1. In an excavating bucket, a supporting frame, jaws rockably mounted on the frame, lift cables for the bucket, and hydraulic rams including cylinders and pistons, means pivotally connecting the cylinders to the frame, and means pivotally connecting the pistons to the jaws.

2. In an excavating bucket, a supporting frame, a pair of bucket jaws having upstanding ears on their inner ends, means pivotally connecting the ears to the outer ends of the frame, upstanding arms formed on the upper front edges of the jaws, hydraulic rams including pistons and cylinders, means pivotally connecting the cylinders to the frame, and means pivotally connecting the pistons to the arms.

3. In an excavating bucket, a supporting frame, jaws rockably mounted upon said frame, hydraulic rams including cylinders and pistons, means pivotally connecting the cylinders to the frame, and means pivotally connecting the pistons to the jaws, a liquid pump, conduits connecting one of the ports of the pump with the inner ends of the cylinders, conduits connecting the outer ends of the cylinders with the other port of the pump, and means for driving the pump in opposite directions.

4. In an excavating bucket, a frame, jaws rockably mounted 'upon the frame, hydraulic rams for opening and closing the jaws including cylinders and pistons, means pivotally connecting the cylinders to the frame, and means pivot-ally connecting the pistons to the jaws, a rotary pump, conduits connecting the inner ends of the cylinders to one port of the pump, conduits connecting the outer ends of the cylinders to the other port of the pump, and a reversible electric motor for operating the rotary pump in either direction.

JOEL M. ROBERTS. 

